1. Field of the Invention
The present invention relates to a female member of a snap fastener, in particular to a female member used by sewing it on clothes, such as blouse, with a thread.
2. Description of the Prior Art
A female member of this type having a construction, in which a cylindrical member 42 provided with a dented portion 41, in which a projecting portion of a male member is inserted, is projected from a center of a base member 40 made of a metal, such as brass, said cylindrical member 42 being provided with an almost S letter-shaped bent clip spring 43 on a base portion thereof, as shown in FIG. 8, has been known for a long time. Reference numeral 44 designates a sewing hole.
However, a female member having the above described construction is strong and durable but the minute clip spring 43 must be calked on the base member 40 after the base member 40 was worked in an appointed shape. That is to say, a disadvantage has occurred in that the manufacturing process is complicated and the cost of production is increased. Also the following disadvantages have occurred.
That is to say, recently clothes and the like have a tendency to be produced by means of a machine, that is to say to be "automatically" produced, and as a result, to be mass-produced. However, with the above described conventional female member, since the base member 40 is provided with the clip spring 43 on one side (the opposite surface side) thereof, its face and back can not but being unsymmetrical. Moreover, since a female member of this type is generally remarkably small and flat in shape, it has been difficult to distinguish its face from its back by means of an automatic sorting machine. This has been an obstacle to the automatization of sewing. In addition, also in the case of hand-sewing, for example it is necessary to pay close attention to the discrimination between the face and the back of the female member. This has led to an increase of the cost of production of clothes.
In addition, although the production of a female member by molding resins have been tried many times, merely the elasticity of resins themselves used as materials has been utilized, that is to say it has never possessed the structural elasticity which is an essenstial function proper to the member. In short, a dented portion of a female member, in which a projecting portion of a male member is to be inserted, has never structurally possessed the elastical function but an inside circumference of the dented portion of the female member has been slightly reduced than an outside circumference of the projecting portion of the male member to put the male member in the female member utilizing the flexibility of resinous material themselves of each member. Accordingly, a problem has occurred also in that an engaging manner determining the proper quality of metallic members obtained by utilizing a clip spring has never been obtained and the durability, such as engaging strength and holding power, is lowered due to the engaging operation repeated many times.